Unit 2: The Ordered Universe Assignment
1. Why was the Ptolemaic system accepted as an explanation of celestial motion for over a thousand years? What did it explain? What system challenged the idea that Earth was the center of the universe?
The Ptolemaic system says that the Earth is the center of the universe. Everything else surrounded the Earth. The Copernican system challenged the belief that Earth was the center of the universe. The major difference between the Ptolemaic and Copernican universes is that the Copernican universe puts the Sun at the center rather than the Earth. Both systems both assumed that all orbits are circular though.
2. What were Tycho Brahe’s principal contributions to science? How did he try to resolve the …show more content…

This simple observation led Newton to recognize two different kinds of motion. An object is in uniform motion if it travels in a straight line at constant speed. All other motions are called acceleration. Accelerations can involve changes of speed, changes of direction, or both. Scholars felt if the object is perfectly round will continue moving unless interfered.
7. Why gravity is called a universal force? What is the difference between g and G?
Newton's law of universal gravitation says between any two objects in the universe there is an attractive force (gravity) that is proportional to the masses of the objects and inversely proportional to the square of the distance between them. In other words, the more massive two objects are, the greater the force between them will be, and the farther apart they are, the less the force will be. Force is something that produces a change in the state of motion of an object. With that being said, gravity is everywhere in our universe, so it become a gravitational force between objects.
Where G is the universal gravitational constant that applies to any two masses anywhere in the universe, g applies only to Earth's surface. It (constant g) also expresses the number of two masses of two objects and their separation.
8. What similarities did Newton see between the Moon and an apple?
Newton saws similarities between the Moon and an apple in the relationship of gravity and force. He questioned